.container {
    max-width: 800px;
    margin: 5% auto;
    padding: 50px;
    background-color: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-sizing: border-box;
    box-shadow: 0 10px 35px rgba(0, 0, 0, 0.4);
  }
  
.lightbox-gallery {
    display: flex;
    flex-direction: row;/* direccion en la que se colocan los hijos*/
    flex-wrap: wrap; /*Los elementos hijos estan colocados en varias lineas*/
    justify-content: center;
}

.lightbox-gallery div img {
    max-width: 100%;
    display: block;
}

.lightbox-gallery div {
    margin: 10px;
    flex-basis: 200px;/*Tamaño inicial de un elemento flexible*/
}  
img.zoom {
    
    width: 300px;
    height: 200px;
    -webkit-transition: all .2s ease-in-out;
    -moz-transition: all .2s ease-in-out;
    -o-transition: all .2s ease-in-out;
    -ms-transition: all .2s ease-in-out;
    transition: all .2s ease-in-out;
    
}
.transition {
    -webkit-transform: scale(1.8); 
    -moz-transform: scale(1.8);
    -o-transform: scale(1.8);
    transform: scale(1.8);
}